The hardest part for me about leaving was losing the "hair standing up on the back of my neck" feeling that I was going to die at Armageddon. Leaving an organization that convinces you that all outsiders will die is very difficult. CoC really helped me because it took many of the dotrines that I had questions about and broke them down for me. I saw another side to the issues. It was nice to realize that I didn't HAVE TO ACCEPT the interpretation presented by Franz, but that it was just another possible way of looking at things. As a witness, that is an entirely new experience.
The other thing that helped me lose my feeling of dread was understanding WHY I was leaving the organization. I still believed in Christianity, morality and God. I just didn't believe in some of the doctrines that JW's taught. Many of those doctrines MUST be accepted to maintain a good standing in the congregation. That was the reason I had to leave, I couldn't accept them. I feel that even if I am wrong, I can honestly stand before God and say that I left for the right reasons. I left in my search for Him and the real "truth."
I would say certainly show him CoC. It helps to show that JW's while, in general, are good people...they don't necessarily have the one and only true religion. My experience is that that is rather comforting while leaving.
Best wishes to both of you. It's a difficult journey. Take it slow. Also, I agree with Joelbear...Do it quietly. There is no reason for him to force the ones that he cares about to shun him.
Take care--TheRedPill